CN202550044U

CN202550044U - Band-stop filter based on coaxial cavities

Info

Publication number: CN202550044U
Application number: CN2012201058379U
Authority: CN
Inventors: 叶强; 罗昌桅; 张苏南
Original assignee: China Jiliang University
Current assignee: China Jiliang University
Priority date: 2012-03-20
Filing date: 2012-03-20
Publication date: 2012-11-21
Anticipated expiration: 2022-03-20

Abstract

The utility model discloses a band-stop filter based on coaxial cavities, which comprises inner conductor resonant rods, an inner conductor main transmission line, supporting insulators, a shell, two N-type connectors and a metal cover. A u-shaped air cavity and a plurality of resonant cavities communicated with the u-shaped air cavity are arranged in the shell. Each resonant cavity is internally and threadedly connected with an inner conductor resonant rod. The inner conductor main transmission line is arranged in the u-shaped air cavity. Both the inner conductor resonant rods and the inner conductor main transmission line are fixed and supported by the support insulators. The inner cores of the two N-type connectors are respectively fixed to the two ports of the coaxial inner conductor main transmission line through soldering tin. The metal cover is covered on the shell to be fixed. The band-stop filter is high in performance due to the adoption of the coaxial cavities and the transmission line transmits TEM modes. Thus, the band-stop filter has the advantages of low passive intermodulation interference, large power capacity, good temperature property and the like, and overcomes the defects of other transmission lines, namely great loss and large volume. The band-stop filter is appropriate for miniaturization design and manufacture, and engineering application.

Description

A kind of band stop filter based on coaxial cavity

Technical field

The utility model relates to the mobile communication equipment technical field, relates in particular to a kind of high resistant attached cavity band stop filter based on the circular coaxial line.

Background technology

In many microwave systems, require signal to transmit therein, and unwanted noise, interference, requirement such as spuious are had the very high degree of decay with as far as possible little decay.For example the interference in certain frequency range is strong especially, and it passes through just must to take special measures to disinthibite.If at this moment take the broadband stopband of band pass filter to suppress unwanted frequency, just not as taking one or several band stop filter to suppress it more flexibly effectively.Some traditional band stop filters (like microstrip line or strip line band stop filter) because its power that can bear is lower, when the spurious signal of power amplifier or the generation of some nonlinear devices is passed through, just puncture easily.And can bear power ratio high Waveguide bandstop filter, at citizens' radio band (probably between 800MHz-2500MHz), device volume is bigger, does not utilize to be integrated in the practical applications.Yet the cavity coaxial band-rejection filter combines the advantage of these two kinds of devices, has that volume is little, to bear power big, advantages such as high stopband inhibition.

Summary of the invention

In order to overcome two kinds of band stop filters of microstrip line and waveguide for the high-power deficiency that can not take into account with miniaturization.The utility model provides a kind of coaxial cavity band stop filter; This filter can not only bear the power about 100W; Volume little (maximal side is in 25cm) is convenient to the through engineering approaches application, and suppresses very high (reaching 80dB) in the band, can effectively suppress interference signal.

The purpose of the utility model is through realize by technical scheme successively: a kind of band stop filter based on coaxial cavity, and it comprises: inner wire resonant rod, inner wire main transmission line, supporting insulator, housing, two N Connectors and crown cap etc.; Wherein, have a U type air chamber and some resonant cavitys that communicates with U type air chamber in the said housing, spin an inner wire resonant rod and fix of each resonant cavity internal thread by nut; The inner wire main transmission line places in the U type air chamber, and inner wire resonant rod and inner wire main transmission line be by the supporting insulator fixed support, makes the top of inner wire resonant rod can not contact with housing with the inner wire main transmission line and causes short circuit; The inner core of two N Connectors is fixed through scolding tin with two ports of the inner wire main transmission line of coaxial line respectively; Crown cap covers on housing and fixes.

The beneficial effect of the utility model is: the utility model adopts coaxial cavity design high-performance band stop filter; This transmission line TEM mould; Have not only that passive intermodulation is low, power capacity is big and advantage such as good temp characteristic; And overcome big, the bulky deficiency of other transmission line losses, be fit to miniaturization Design and manufacturing and practical applications.

Description of drawings

Fig. 1 is the cutaway view of the utility model band stop filter;

Fig. 2 is the end view of inner wire main transmission line among Fig. 1;

Fig. 3 is an A-A cutaway view among Fig. 1;

Fig. 4 is vertical view, left and right sides view and the rearview of the utility model band stop filter;

Among the figure, inner wire resonant rod 1, inner wire main transmission line 2, supporting insulator 3, housing 4, adjusting screw 5, N Connector 6, screw 7, crown cap 8.

Embodiment

Like Fig. 1-shown in Figure 4, the utility model comprises based on the band stop filter of coaxial cavity: inner wire resonant rod 1, inner wire main transmission line 2, supporting insulator 3, housing 4, nut 5, two N Connectors 6 and crown caps 8.Wherein, Have a U type air chamber and some resonant cavitys that communicates with U type air chamber in the housing 4; Each resonant cavity internal thread inner wire resonant rod 1 and fixing that spins by nut 5; Inner wire main transmission line 2 places in the U type air chamber, and inner wire resonant rod 1 and inner wire main transmission line 2 be by supporting insulator 3 fixed supports, makes the top of inner wire resonant rod 1 can not contact with housing 4 with inner wire main transmission line 2 and causes short circuit.The inner core of two N Connectors 6 is fixed through scolding tin with two ports of the inner wire main transmission line 2 of coaxial line respectively; Crown cap 8 covers on housing 4, and fixing by screw 7.

The chamber of resonant cavity is 1/4th resonance wavelengths deeply; Its cutaway view is as shown in Figure 3.The structure of inner wire main transmission line 2 is as shown in Figure 2, and the coaxial line characteristic impedance of two ports of inner wire main transmission line 2 is 50 Europe.

The course of work of the utility model is following: the signal of communication is an input in two N Connectors 6 from Fig. 4; Export from another one N Connector 6 inner chamber (comprising U type air chamber and some resonant cavitys that communicates with U type air chamber) back through whole band stop filter, accomplishes screening of signals.Structure among Fig. 1 is to be made up of 16 capacitive coupling branch lines of an inner wire main transmission line 2 parallel connections (being realized by resonant cavity and the inner wire resonant rod 1 that screws in it).Confirm the characteristic impedance of capacitive coupling branch line according to the actual conditions needs; Change the size of coupling capacitance again through the length of regulating inner wire resonant rod 1, and then regulate resonance frequency, form a complete rejector circuit; Suppress spurious signal, through needed signal.

The utility model emulation and measured result show that measured result and simulation result approach very much.In the stopband of 1980MHz, the emulation of embodiment and actual measurement transfer function curve s21 be all less than-80dB at 1920MHz for signal frequency, and approach very much.And echo function curve s11 all has in to 2.2GHz and 1700MHz to two ultra broadbands of 1910MHz at 1990MHz-return loss below the 15dB and-insertion loss more than the 2dB.Because technology and debugging error, the actual measurement and the emulation of the echo function curve of embodiment have certain error, but its measured result still satisfies the index request of design fully, and can make it approach simulation result through improving machining accuracy and debugging.

Claims

1. the band stop filter based on coaxial cavity is characterized in that it comprises: inner wire resonant rod (1), inner wire main transmission line (2), supporting insulator (3), housing (4), two N Connectors (6) and crown cap (8); Wherein, have a U type air chamber and some resonant cavitys that communicates with U type air chamber in the said housing (4), each resonant cavity internal thread inner wire resonant rod (1) and fixing that spins by nut (5); Inner wire main transmission line (2) places in the U type air chamber; Inner wire resonant rod (1) and inner wire main transmission line (2) be by supporting insulator (3) fixed support, makes the top of inner wire resonant rod (1) can not contact with housing (4) with inner wire main transmission line (2) and cause short circuit; The inner core of two N Connectors (6) is fixed through scolding tin with two ports of the inner wire main transmission line (2) of coaxial line respectively; Crown cap (8) covers at housing (4) to be gone up and fixes.